Jim,
That would be late June (var. citrinum) around the time regale usually flowers. Henryi is always my second lily to flower after the dauricum types.
I can second that observation that in some years my rosthornii pods have barely reached maturity before the first frost. Even if all the seeds are not mature I can usually get enough from the 20 or so stems.
Aaron
--- On Fri, 4/5/13, Jim McKenney <jamesamckenney@verizon.net> wrote:
From: Jim McKenney <jamesamckenney@verizon.net>
Subject: Re: [pbs] Growing Lilium rosthornii for seed
To: "Pacific Bulb Society" <pbs@lists.ibiblio.org>
Date: Friday, April 5, 2013, 1:12 AM
Aaron wrote "My plants usually flower in Aug-September in comparison to henryi which usually flowers in June. "
Aaron, I know you're south of here, but June seems very early for Lilium henryi. Here in USDA zone 7 Maryland, just north of Washington, D.C., it blooms in mid-July.
Griffiths, writing about a century ago, noted that even plants growing in northern Virginia often did not ripen properly outside before freezes; he suggested cutting the stems and maturing them indoors in water.